var a = [];
a["123"] = "a";
a["124"] = "b";
console.log(a.length);//125
$.each(a, function(index,item){
console.log(index, item);//0, undefined; 1, undefined
});
var a = [];
a["123"] = "a";
a["124"] = "b";
console.log(a.length);//125
$.each(a, function(index,item){
console.log(index, item);//0, undefined; 1, undefined
});